In a move that surprised many of Mr Assange’s closest supporters on Saturday, The Guardian newspaper published previously unseen police documents that accused Mr Assange in graphic detail of sexually assaulting two Swedish women. One witness is said to have stated: “Not only had it been the world’s worst screw, it had also been violent.”

Bjorn Hurtig, Mr Assange’s Swedish lawyer, said he would lodge a formal complaint to the authorities and ask them to investigate how such sensitive police material leaked into the public domain. “It is with great concern that I hear about this because it puts Julian and his defence in a bad position,” he told a colleague.

“I do not like the idea that Julian may be forced into a trial in the media. And I feel especially concerned that he will be presented with the evidence in his own language for the first time when reading the newspaper. I do not know who has given these documents to the media, but the purpose can only be one thing – trying to make Julian look bad.”

In today’s Guardian editorial, the newspaper explained why it had chosen to publish the sexual misconduct allegations in detail: “It is unusual for a sex-offence case to be presented outside of the judicial process in such a manner, but then it is unheard of for a defendant, his legal team and supporters to so vehemently and publicly attack women at the heart of a rape case.”

The paper is reflecting a growing discomfort among many, in both camps, at the widespread vilification – and naming – of the two alleged victims on websites and blogs, and also of the kind of language being used by people including Assange’s own lawyer Mark Stephens who referred to the allegation as a “honeytrap” .

“I have never heard the like. Legal representatives do not and should not stand on the steps outside a court of law and make such comments about their clients, it is neither right nor fitting,” said one outraged barrister. “It is certainly in my view deeply unprofessional.”